Colour filters are widely used in photography and liquid crystal display devices. Generally the filters contain filter elements of three different colours, typically red, green and blue. Colour filters filter light by wavelength range, such that separate filtered intensities include information about the colour of light.
Numerous techniques have been employed to form colour filters, including the use of photoresists, deposition of organic pigments by vacuum evaporation followed by conventional photolithographic lift-off techniques, the use of dyed and patterned stretched film material to create an internal colour polarising filter, and the use of conventional silver halide photosensitive layers. Prior art techniques for forming colour filters are described for instance in U.S. Pat. No. 4,743,098 and U.S. Pat. No. 5,578,404. Some of these techniques are expensive and time consuming and there remains a desire to provide improved methods for forming colour filters.